PS and more than one GPU

Hello!
I use PC win7 64bit with three GPUs installed on it.
The first one is GTX770 for display, it's plugged to main pci-e x16 slot.
Second and third are GTX780 and are plugged to additional pci-e slots.

When I start Photoshop (СС 2014.2.2 version) there are some load with some memory consumption appears on GPUs #2 and #3.
GPU #1 takes some load too but it's ok. It is clear.

In other words there might be no work at Ps. Just opened application without any files. And loading at all cards starts.
Ps uses only GPU #1, but load all of them.
Thereby power consumption growths, temperature growths, noise level also growths. With no reason and no efficiency.

Could You fix it, please?

Hm.... The Ps works good, it's ok. But if it uses really just one GPU, then why it loads other GPUs?

Yeah. You can say something like "remove other GPUs". But I use them for render.
Buy second PC is expensive and uncomfortable solution. Unplug GPUs to use Ps and then plug in to use render - crazy idea. Do you think so? )